The invention relates to a machine for the comminution of bulk material such as wood refuse or the like.
In one known machine of this type (DE-OS No. 2701 897) all the cutting edges of the rotor have identical length. Each cutting edge of the rotor circumscribes the same path of an annular working plane. The cutting edges of the stator which cooperate with the cutting edges of the rotor within one and the same step of comminution have among each other the same length also and therefore, among themselves, the same overlap with the annular working plane of the rotor cutting edges.
When one object or a plurality of objects reaches simultaneously a cutting edge of the rotor and the cutting edge of the stator nearest in the direction of rotation, comminution in that step of comminution occurs in one single cut. This cut is particularly in the case of comparatively rigid and/or also thicker and wider objects not a cut at a point which is advantageous for the use of power but rather an impact cut which shears through the whole length of the object. This causes high peak loads and frequent blocking, both occurrences which may deleteriously influence some parts of the machinery and the comminution process.
As objective of the present invention is the creation of a machine of the aforedescribed kind which cuts the material to be comminuted within one step of comminution in a plurality of consecutive partial cutting processes.
The machine according to the invention obtains efficient comminution of a great variety of objects, particularly objects of great bulk and/or material solidity by using simple means of construction of the machine at an increased service life. Furthermore, stand still periods due to blockages are considerably decreased.